Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D239/00—Heterocyclic compounds containing 1,3-diazine or hydrogenated 1,3-diazine rings
  • C07D239/02—Heterocyclic compounds containing 1,3-diazine or hydrogenated 1,3-diazine rings not condensed with other rings
  • C07D239/24—Heterocyclic compounds containing 1,3-diazine or hydrogenated 1,3-diazine rings not condensed with other rings having three or more double bonds between ring members or between ring members and non-ring members
  • C07D239/26—Heterocyclic compounds containing 1,3-diazine or hydrogenated 1,3-diazine rings not condensed with other rings having three or more double bonds between ring members or between ring members and non-ring members with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to ring carbon atoms
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C33/00—Unsaturated compounds having hydroxy or O-metal groups bound to acyclic carbon atoms
  • C07C33/02—Acyclic alcohols with carbon-to-carbon double bonds
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07D—HETEROCYCLIC COMPOUNDS
  • C07D285/00—Heterocyclic compounds containing rings having nitrogen and sulfur atoms as the only ring hetero atoms, not provided for by groups C07D275/00 - C07D283/00
  • C07D285/01—Five-membered rings
  • C07D285/02—Thiadiazoles; Hydrogenated thiadiazoles
  • C07D285/04—Thiadiazoles; Hydrogenated thiadiazoles not condensed with other rings
  • C07D285/12—1,3,4-Thiadiazoles; Hydrogenated 1,3,4-thiadiazoles
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K19/00—Liquid crystal materials
  • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
  • C09K19/06—Non-steroidal liquid crystal compounds
  • C09K19/34—Non-steroidal liquid crystal compounds containing at least one heterocyclic ring
  • C09K19/3441—Non-steroidal liquid crystal compounds containing at least one heterocyclic ring having nitrogen as hetero atom
  • C09K19/345—Non-steroidal liquid crystal compounds containing at least one heterocyclic ring having nitrogen as hetero atom the heterocyclic ring being a six-membered aromatic ring containing two nitrogen atoms
  • C09K19/3458—Uncondensed pyrimidines
  • C09K19/3463—Pyrimidine with a carbon chain containing at least one asymmetric carbon atom, i.e. optically active pyrimidines
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K19/00—Liquid crystal materials
  • C09K19/04—Liquid crystal materials characterised by the chemical structure of the liquid crystal components, e.g. by a specific unit
  • C09K19/06—Non-steroidal liquid crystal compounds
  • C09K19/34—Non-steroidal liquid crystal compounds containing at least one heterocyclic ring
  • C09K19/3491—Non-steroidal liquid crystal compounds containing at least one heterocyclic ring having sulfur as hetero atom
  • C09K19/3497—Non-steroidal liquid crystal compounds containing at least one heterocyclic ring having sulfur as hetero atom the heterocyclic ring containing sulfur and nitrogen atoms
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K2323/00—Functional layers of liquid crystal optical display excluding electroactive liquid crystal layer characterised by chemical composition
  • C09K2323/02—Alignment layer characterised by chemical composition
  • C09K2323/027—Polyimide

Definitions

• the present invention relates to novel liquid-crystalline allenes of the formula I ##STR2## where M is a mesogenic group,
• R 1 and R 2 are hydrogen or a C-organic radical having 1-8 carbon atoms
• R 3 is a C-organic radical having 1-30 carbon atoms
• X 1 is --(CH 2 ) q --O--(CH 2 ) p --
• R 4 is hydrogen or an alkyl radical having 1-4 carbon atoms
• p is from 1 to 20
• q is from 0 to 20
• R 2 and R 3 can also be interchanged.
• the present invention furthermore relates to the preparation of the novel liquid-crystalline compounds, to novel allenes as intermediates for coupling to mesogenic groups, and to the use of liquid-crystalline compounds in optical display elements, in optical, electronic and electro-optical storage media, in electrophotographic instruments and in light-reflecting layers.
• liquid-crystalline compounds are employed for many purposes in the electro-optical field. Mention may be made here by way of example of optical storage systems (DE-A-38 27 603 and DE-A-39 17 196), electrophotography (DE-A-39 30 667), liquid-crystalline display elements (Mol. Cryst. Liq. Cryst. 114 (1990) 151) and, in the case of ferroelectric liquid-crystalline media, electrical storage systems (Ferroelectrics, 104 (1990) 241). Ferroelectric materials exhibit permanent polarization when they are introduced into an electric field, ie. they retain their alignment after the field has been switched off again. The phenomenon of ferroelectricity is also exhibited by certain liquid-crystalline compounds which have a chiral structure.
• S c * phases smectic liquid-crystalline C phases
• the long molecular axes are inclined to the layer normals Z within each individual layer.
• the direction of this inclination is given by the director n.
• S c * phases have two stable states with different directions of n, between which switching can be effected by applying an electric field (electro-optical effect).
• Ferroelectric liquid crystals are used in particular in electro-optical display elements which operate on the principle of the surface stabilized ferroelectric liquid crystal (SSFLC). These display elements generally contain mixtures of liquid-crystalline compounds which are either themselves chiral or in which chirality is induced by the presence of chiral substances. The properties of the liquid-crystalline compounds in these display elements are subject to severe demands. A relatively low spontaneous polarization and low rotational viscosity are desirable in order to achieve fast response times. In addition, a broad phase width is desired for the S c * phase. With respect to these properties, known liquid-crystalline compounds are unsatisfactory.
• the substituents R 1 and R 2 can be hydrogen or C-organic radicals having 1-8 carbon atoms. Besides pure alkyl groups, chains interrupted by oxygen or nitrogen, for example --CH 2 --CH 2 --O--CH 2 --CH 3 or CH 2 --CH 2 --NH--CH 2 --CH 3 , are also suitable. However, preference is given to short alkyl radicals, such as methyl, ethyl and propyl, and hydrogen.
• R 3 and R 5 are C-organic radicals having 1-30 carbon atoms. Preference is given to radicals of the type which have an essentially linear structure, ie., for example, straight-chain alkyl or alkyl which is interrupted by oxygen, nitrogen, ester or amide groups. Preference is given to alkyl radicals having 4-12 carbon atoms, particularly preferably those having 5-9 carbon atoms, very particularly preferably n-heptyl.
• liquid-crystalline compounds I are prepared from allenes of the formula II ##STR3##
• allenes II carry, for coupling to the mesogenic group M, a hydroxyl, amino or carboxyl group which is bonded to the allene group via a --(CH 2 ) p -- group, where p is a number from 1 to 20, preferably from 1 to 8, particularly preferably 1. Particular preference is given to the allene intermediate ##STR4## and its enantiomer.
• Preferred radicals R 3a are those mentioned above for R 3 , but having not more than 6 carbon atoms. Preference is given to linear alkyl groups having 7 to 11 carbon atoms, particularly preferably n-heptyl.
• chiral allenes exhibit particular liquid-crystalline properties, they are also particularly preferred for these intermediates. Particular preference is likewise given to mixtures of enantiomers in which one enantiomer is present in an excess of at least 60:40.
• the mesogenic group M preferably has the structure Ia
• ring groups A are substituted and unsubstituted iso- and heteroaromatic groups, such as ##STR6## where Hal is halogen or pseudohalogen, particularly preferably F, Cl or CN, and nonaromatic ring structures, such as ##STR7##
• the liquid-crystalline allenes are preferably prepared by synthesizing the mesogenic group and the allene moiety separately.
• the allene moiety carries, as functional coupling group, a hydroxyl, amino or carboxyl group, coupling via a hydroxyl group with formation of an ether bond to the mesogenic group being preferred.
• the allenes of the formula II are obtainable in a manner known per se via several steps, for example in the following sequence starting from the corresponding alkynols (for X 2 ⁇ --NR 4 -- or --O--CO--, starting from the corresponding alkynamines or alkynecarboxylic acids).
• R * is a protecting group, preferably a silyl group, particularly preferably tert-butyldiphenylsilyl.
• the oxidation can be carried out using various oxidants, preferably pyridinium chlorochromate (PCC).
• PCC pyridinium chlorochromate
• the reducing agents are preferably optically active boranes, particularly preferably optically active B-3-pinanyl-9-borabicyclo 3.3.1!nonane (Alpine-Borane).
• the brominating agent is preferably CBr 4 in the presence of triphenylphosphine.
• R 2 here is hydrogen if an aldehyde was employed in step b). If a ketone was employed, R 2 is a C-organic radical having 1-8 carbon atoms.
• the allene formation is preferably accomplished with the aid of a cuprate, which is formed, for example, in situ from CuI and a Grignard compound. This reaction allows a desired substituent R 1 to be introduced into the allene.
• the silyl protecting group is preferably removed using tetrabutylammonium fluoride.
• the suitable condensation agent for coupling of the allene to the mesogenic group depends on the nature of the functional groups provided for the coupling.
• An alcohol is reacted with a phenolic hydroxyl group of the mesogenic group, preferably by means of diethyl azodicarboxylate/triphenylphosphine.
• a phenolic hydroxyl group of the mesogenic group preferably by means of diethyl azodicarboxylate/triphenylphosphine.
• diethyl azodicarboxylate/triphenylphosphine for coupling of a hydroxyl or amino group to a carboxyl group, use can be made, for example, of carbodiimides or carbonyldiimidazole.
• novel liquid-crystalline allenes can be used alone or in combination with other compounds.
• combinations with substances which modify the temperature range or width of the liquid-crystalline phases in a desired manner are advantageous.
• Liquid-crystalline allenes are used in the production of electro-optical display elements, in optical, electronic and electro-optical storage media, in electrophotographic instruments and in light-reflecting layers.
• a particularly preferred use of the novel compounds is in SSFLC displays, since, through their ferroelectric properties, their relatively low spontaneous polarization and low rotational viscosity, they have a particularly favorable switching behavior.
• the racemic compound was obtained by direct reaction of the protected propargyl alcohol 2! as described in Example 1d to give the bromide rac-5! and analogous further reactions.
• the compound was obtained by condensation of the allene alcohol 2-methylundeca-2,3-dien-1-ol (rac-7, obtainable analogously to Example 1f) with the mesogenic compound ##STR19## analogously to the reaction described in Example 1g.
• phase transition temperatures were determined as usual using a polarizing microscope (Leitz Ortholux II pol) in combination with a microscope heating stage (Mettler FP 800/82).

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• Engineering & Computer Science (AREA)
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• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
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• Liquid Crystal (AREA)

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• 1995
  • 1995-03-30 DE DE19511448A patent/DE19511448A1/de not_active Withdrawn
• 1996
  • 1996-03-25 EP EP96104699A patent/EP0735125A3/de not_active Ceased
  • 1996-03-27 US US08/624,918 patent/US5695681A/en not_active Expired - Fee Related
  • 1996-03-29 JP JP8077389A patent/JPH08337777A/ja not_active Withdrawn

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